UPSC CSE Prelims
Question 78
Consider the following:
- Aerosols
- Foam agents
- Fire retardants
- Lubricants
In the making of how many of the above are hydrofluorocarbons used?
View correct answer and explanation
Correct answer: C
Correct Option: C (Only three)
Explanation: Hydrofluorocarbons have been used as aerosol propellants, foam-blowing agents and in some fire-extinguishing formulations; lubricants are a separate materials category.
Statement / Pair / Item-wise Analysis:
1. Correct/True - Some aerosols use HFC propellants.
2. Correct/True - HFCs have served as blowing agents in insulation foams.
3. Correct/True - Certain HFC-based fire-suppression agents replaced ozone-depleting halons.
4. Incorrect/False - Lubricants are typically formulated using mineral/synthetic oils and additives, not HFCs as the listed application.
Option-wise Analysis:
A. Incorrect-it counts 1, but items 1, 2, 3 qualify, giving 3.
B. Incorrect-it counts 2, but items 1, 2, 3 qualify, giving 3.
C. Correct-exactly 3 of the 4 listed items satisfy the condition.
D. Incorrect-it counts 4, but only 3 qualify; item(s) 4 do not.